AB1628 THE INCIDENCE AND PREVALENCE OF RHEUMATOID ARTHRITIS IN ITALY IN THE LAST DECADE
Authors: M. Zen, L. Salmaso, C. Barbiellini Amidei, A. Giollo, U. Fedeli, S. Bellio, F. Arru, I. Gennaio, M. Saia, A. Doria
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Rheumatoid arthritis (RA) prevalence is believed to be around 1% worldwide, although it varies considerably among different populations.[1] Several environmental factors such as smoking, certain infections, and diet contribute to the risk of RA and differ between populations.[2] The pooled prevalence of RA was estimated to be 0.54% (95% CI 0.50–0.59) in Europe,[1] but no studies have recently evaluated the epidemiology of RA in Italy. <h3>Objectives</h3> We aimed at estimating the incidence and prevalence of RA in northeastern Italy over the period 2012–2020. <h3>Methods</h3> A retrospective population-based study was conducted in the Veneto Region (4.9 million people) using the Population Registry, an administrative health database where all residents are recorded. The population registry was linked with healthcare co-payments exemptions, hospital discharge records, and mortality records. Between 2012 and 2020, RA prevalence was defined by a healthcare copayment exemption for RA (national registry code 006) or any hospital diagnosis of RA (ICD-9-CM 714.x), whichever came first. Incident RA was defined from 2013 to 2020 to exclude prevalent cases. Standardized incidence and prevalence rates were reported by age and gender. <h3>Results</h3> During the study period, we identified 37,996 prevalent RA patients, with 12,875 incident cases. Across the study period, RA standardized prevalence increased from 0.50% (95% CI 0.50; 0.51) to 0.57% (95% CI 0.57; 0.58). RA point prevalence in 2020 according to gender and age is reported in Figure 1. RA incidence corresponded to 33.1 (32.5; 33.7) per 100,000 person-years, with the lowest incidence observed in the last two years of the study: 27.4 (25.9; 28.9) in 2020 and 32.2 (30.6; 33.8) in 2019 (Table 1). The peak for both prevalence and incidence was around the eighth decade of life. Incidence was 2-times higher in females: female-to-male incidence rate ratio (IRR) 2.3 (2.2; 2.4) (p&lt;0.0001), with a peak among people aged 20-29 years, where female-to-male IRR was 3.1 (2.4; 3.9) and the lowest value among patients aged ≥70 years, where F:M IRR was 1.6 (1.4; 1.8). <h3>Conclusion</h3> The prevalence of RA in Italy is 0.57%, in line with data from other European countries. Incidence was confirmed to be higher among females, especially in younger patients. <h3>References</h3> [1]Almutairi K et al. The global prevalence of rheumatoid arthritis: a meta-analysis based on a systematic review. Rheumatol Int 2021;41:863–877. [2]Tobon, GJ, et al. The environment, geo-epidemiology, and autoimmune disease: Rheumatoid arthritis. J Autoimmun 2010;35:10–14. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> Margherita Zen Speakers bureau: Abbvie, Ely Lilly, GSK, Galapagos, AstraZeneca, Laura Salmaso: None declared, Claudio Barbiellini Amidei: None declared, Alessandro Giollo Speakers bureau: Galapagos, Abbvie, Ugo Fedeli: None declared, Stefania Bellio: None declared, Federico Arru: None declared, Ilenia Gennaio: None declared, Mario Saia: None declared, Andrea Doria Speakers bureau: GSK, AstraZeneca, UCB, Pfizer, Consultant of: GSK, AstraZeneca.